In general, a field coil assembly of an electromagnetic clutch for a compressor is an electric device that transmits a driving force of a pulley rotated by an engine to a disk 4a of a hub 4 engaged with a driving shaft 2 of a compressor 1, by producing a magnetic field by means of electromagnetic induction of an electromagnetic coil at the time of the supply of the electric power, and allowing the disk 4a of the hub 4 engaged with the driving shaft 2 of the compressor 1 to be suctioned to the side of a frictional surface 3a of the pulley 3 by the magnetic force to dynamically be connected to it.
Instantly, it functions to control the operation of the cooling system of an air conditioning device by regulating the power supplied to the compressor according to the application of the electric power to the electromagnetic coil.
As shown in FIGS. 1 to 4, the field coil assembly of an electromagnetic clutch for a compressor comprises a field coil portion 10a and a sleeve 21, and the field coil portion 10a includes an electromagnetic coil body 11 formed of electromagnetic coils wound into a ring shape, a bobbin 12 formed with a projection 12a to expose a pair of coil lines 11a withdrawn from the electromagnetic coil body 11 and instantly receiving the electromagnetic coil body 11, a core ring 15 for accommodating the bobbin 12 receiving the electromagnetic coil body 11 and inserted into the pulley 3, thereby being secured to the compressor 1, and a cover 13 for tightly closing an open surface of the core ring 15 so that the electromagnetic coil body 11 and the bobbin 12 are not separated from the core ring 15.
Also, a flange 16 is engaged with one side of the core ring 15, and the flange 16 is formed with locking portions 16a at both sides of the pair of coil lines 11a. 
In addition, the sleeve 21 is engaged with the locking portions 16a of the field coil portion 10a, and a terminal 21a is mounted at the inside of the sleeve 21 in such a manner as to be electrically connected at one end thereof to an end of electric wire 20 and connected at the other end thereof to the coil lines 11a so as to cause an external power source to be connected to the electromagnetic coil body 11.
Herein, the sleeve 21 is disposed at one end of the electric wire 20, and a connector 22 is disposed at the other end of the electric wire so that it can be connected to a separate connector 5 for supplying the external electric power therethrough.
In other words, the sleeve 21 and the connector 22 are formed at both ends of the electric wire 20 by molding both ends of the electric wire 20 with resin after injecting the electric wire 20 into an injection mold. In this instance, the sleeve 21 is formed by performing the insert-molding of the terminal 21a into one end of the electric wire 20 after it is previously secured.
Thus, the sleeve 21, which is performed of the insert-molding into one end of the electric wire 20, is engaged with the locking portions 16a of the field coil portion 10a. In this instance, a product is manufactured by finally performing the insert-molding of a connection portion of the terminal 21a and the coil lines 11a so that it is not exposed to the outside, because the terminal 21a and the coil lines 11a are electrically connected to each other.
Accordingly, it is possible to produce a magnetic field at the electromagnetic coil body 11 by connecting the connector 22 of the electric wire 20 to the separate connector 5 connected to the external power source.
Meanwhile, in the field coil assembly 10 of the electromagnetic clutch, when the supply of the electric power to the electromagnetic coil body 11 is interrupted, surge voltage and reverse electromotive force are generated at the electromagnetic coil body 11, thereby causing bad affects such as occurrence of shortening, and the like to the surrounding other electric and electronic products.
Accordingly, it is possible to maintain the voltage at normal state by preventing the generation of the surge voltage and the reverse electromotive force by disposing a diode (not shown) or a register (not shown) at the inside of the sleeve 21 or the connector 22 or at the electric wire 20.
However, conventionally, the electric wire 20 was injected into the injection mold to form the sleeve 21 at one end of the electric wire 20. In this instance, there occurred problems that the electric wire 20 was sometimes pierced by the mold during the injection molding, thereby damaging the electric wire 20 and the cladding of the electric wire in addition to the increase of the disorder ratio due to the injection disorder, and the like.
Moreover, there occurred a problem that manufacturing expense such as material expense, or labor expense, and the like was increased, because a separate member such as contraction tube, and the like should be additionally assembled to an outer shell of the electric wire 20 to protect the electric wire 20.
Furthermore, since both ends of the electric wire 20 should be performed of the injection-molding instantly with the sleeve 21 and the connector 22, it was difficult to adjust the length of the electric wire 20. In other words, conventionally, there also occurred a problem that a separate accommodating structure should be formed in the injection molding according to the length of the electric wire 20 to adjust the length of the electric wire 20.